The present invention relates to a protective cover for placement over an opening between adjoining horizontal structures. The present invention is more particularly related to cover assemblies that form a bridge over a gap or opening between two horizontal concrete structures. The cover assemblies of the present invention are especially useful to allow a smooth transition of traffic, particularly vehicular traffic, without damage to the structural members and expansion material in a gap between the adjoining horizontal structures.
An expansion joint is formed by placing a mass of expansion material in a gap purposely provided between adjoining concrete structures for accommodating dimensional changes to the gap occurring as expansion and contraction due to temperature changes and/or seismic cycling and vibration. The expansion joint may also be damaged by the ingress of surface water but, particularly, by abrasion and compression forces generated by the passage of motorized vehicular traffic.
Expansion joints, particularly in sports stadiums, parking garages and airports are degraded when the expansion material must bear the wear and tear caused by contact with service vehicles, such as fork lifts or other vehicles used to transport supplies and equipment along corridors formed by concrete structures. The expansion material is often ejected from the gap between the concrete structures when the adhesion between the concrete material and the expansion material degrades allowing the ingress of water and development of damaging forces generated at freezing temperatures. A degradation to the expansion material may also occur by the passage of vehicular traffic, particularly when concrete structures form an uneven passageway resulting in impact loading on the structures by the traffic.
Elongated metal plates placed in an end-to-end relationship have been bolted to the concrete structure in an attempt to protect the expansion joint from damage due to pedestrian and vehicular traffic. Often, the metal plates become deformed and do not form a uniform seated engagement with concrete structures particularly where the traffic bearing upper surfaces of the adjoining concrete structures are irregular or undulating, which fails to provide the necessary uniform planar support for the metal plates. The metal plates are bent and distorted due to impact loading of traffic and acquire a state of looseness about their mounting bolts which degrades further when the mounting bolts eventually shear. Even before the metal plates become disjointed from the mounting bolts, the metal plates generate an annoying noise with each deflection against the adjoining concrete structures.
Additionally, it is widely known that the surfaces of concrete structural members are not always entirely uniform, and are often not produced with square or smooth surfaces. These concrete structural members are usually rough, often have substantially irregular or undulating gaps, or are missing entire chunks of concrete. Furthermore, there is often a vertical xe2x80x9coffsetxe2x80x9d between two structural members, due to the settlement of concrete.
Therefore, a need exists in the art for an improved cover assembly to bridge gaps or openings between structural members to provide a smooth transition over the gap and to substantially reduce the trip hazard for pedestrians. There is also a need to provide a cover assembly to protect expansion joint material in a gap between structural members, such as concrete structures.
The present invention provides a cover apparatus for a gap between structural members having the resiliency to conform to the configuration of the support sites provided by structural members.
The present invention also provides a resilient cover apparatus combined with members for adding mass to the cover to stabilize the cover particularly during the passage of traffic.
The present invention further provides a resilient cover with parallel spaced apart elongated plate members supported by a face surface of the cover directed toward a gap or opening between structural members to stabilize opposite lateral edges of the resilient cover undergoing elastic deformation by traffic.
These and other aspects of the present invention are accomplished by the cover assembly and method of installation which is hereafter described and claimed. The aspects and advantages of the invention may be realized and attained by means of the embodiments and combinations particularly pointed out in the attached claims.
Accordingly, the present invention provides a cover assembly for a gap between two horizontal structural members comprising: an elongated resilient cover having a load bearing surface opposite a support surface including marginal support areas along opposite lateral edges thereof, said cover having a thickness and sufficient elasticity to elastically deform for establishing supporting contact between said marginal support areas and underlying horizontal structural members adjacent to a gap between said structural members; a rigid plate member, secured along said support surface of said elongated resilient cover by an attachment means, for bridging a gap between said horizontal structural members; and a plurality of fasteners engaged with said cover at spaced apart sites along at least one lateral side portion of said cover for elastically anchoring said elongated resilient cover to at least one of the horizontal structural members.
In another embodiment, the present invention provides a cover assembly that further comprises at least two rigid plate members secured along said support surface of said elongated resilient cover by an attachment means to extend along opposite lateral sides of said rigid plate member.
The present invention also provides a cover assembly for a gap between horizontal structural members comprising: an elongated resilient cover having a predetermined width sufficient to overlie portions of horizontal structural members outwardly of marginal edges to a gap between the horizontal structural members; a rigid plate member, secured to said elongated resilient cover by an attachment means, for stabilizing said cover while traffic traverses said cover, said rigid plate member defining an elongated bridging member having a width sufficient to span the width of a gap between said horizontal structural members while secured thereby; and a plurality of fasteners to anchor said resilient cover along at least one marginal edge of said resilient cover to at least one of said horizontal structural members.
In another embodiment, the present invention provides a cover assembly that further comprises at least two rigid plate members secured to said resilient cover by an attachment means and being restrained by said resilient cover to extend in a side-by-side relation to said elongated bridging member.
The present invention also provides an expansion joint for a building structure comprising: two spaced apart structural members defining a gap therebetween; and a cover assembly comprising an elongated resilient cover having a load bearing surface opposite a support surface including marginal support areas along opposite lateral edges thereof, said cover having a thickness and sufficient elasticity to elastically deform for establishing supporting contact between said marginal support areas and underlying horizontal structural members adjacent an expansion joint; a rigid plate member, secured along said support surface of said elongated resilient cover by an attachment means, for bridging a joint formed in a gap between said horizontal structural members; and a plurality of fasteners engaged with said cover at spaced apart sites along at least one lateral side portion of said resilient cover to elastically anchor said elongated resilient cover to at least one of the horizontal structural members.
In another embodiment, the present invention provides a cover for an expansion joint, wherein said cover further comprises at least two plate members restrained along said support surface by said elongated resilient cover to extend along opposite lateral sides of said rigid plate member for allowing elastic deformation of said cover and apply a biasing force in a direction to urge opposite lateral sides of said cover toward the horizontal structural members while resiliently deformed by traffic traversing said load bearing surface.
The present invention also provides a method for the installation of a cover assembly across a gap between two structural member comprising: providing a cover assembly comprising an elongated resilient cover having a load bearing surface opposite a support surface including marginal support areas along opposite lateral edges thereof, said cover having a thickness and sufficient elasticity to elastically deform for establishing supporting contact between said marginal support areas and underlying horizontal structural members; a rigid plate member, secured along said support surface of said elongated resilient cover by an attachment means, for bridging a joint formed in a gap between said horizontal structural members; and a plurality of fasteners engaged with said cover at spaced apart sites along at least one lateral side portion of said resilient cover to elastically anchor said elongated resilient cover to at least one of the horizontal structural members; and placing said cover assembly across said gap.
In another embodiment, the method of installation utilizes a cover assembly that further comprises at least two plate members restrained along said support surface by said elongated resilient cover to extend along opposite lateral sides of said rigid plate member for allowing elastic deformation of said cover and apply a biasing force in a direction to urge opposite lateral sides of said cover toward the horizontal structural members while resiliently deformed by traffic traversing said traffic bearing surface.